In an attempt to abrogate the deleterious effects of graft-versus-host disease (GVHD), allogeneic transplantation for nonmalignant diseases was performed using high-dose CD34-cell infusion, partial T cell depletion, and no posttransplantation GVHD prophylaxis. Between 1998 and 2004, 16 patients with matched related donors were treated. Median age was 1.5 years (range, 5 months-18 years). The conditioning regimen consisted of busulphan 16 mg/kg, cyclophosphamide 200 mg/kg, antithymocyte globulin (ATG) 25 mg/kg, and fludarabine 200 mg/m(2). No GVHD prophylaxis was given. High doses of CD34 cells, positively selected by immunomagnetic beads, were infused at a median dose of 10.7 x 10(6) CD34/kg (range, 7.4-50 x 10(6)). A total of 1 x 10(5)/kg T cells were given. All patients engrafted, with no graft rejections. All were alive and well at a median of 37 months posttransplantation (range, 18-89 months). Only 1 patient developed chronic GVHD. No episodes of severe infection occurred during or after transplantation. Immunologic reconstitution with CD3/CD4 T cells > 200/microL was observed at a median of 117 days and that with naive T cells (CD4/CD45RA) at a median of 188 days posttransplantation. Our findings suggest that allogeneic transplantation from a matched family donor for nonmalignant disorders can be successfully performed using high doses of CD34 cells, moderate T cell depletion, and no posttransplantation immunosuppression.